1. Field of the Invention
The invention relates to a container having hinged lids that are able to be snap fit onto the container, and to a method of molding and assembling a hinged lid container in which the lids are molded at the same time as the container and are assembled onto the container as the container and lids are ejected from the mold cores in the molding process.
2. Description of Related Art
Stackable and nestable hinged lid containers or totes are well known and widely used. Half lids extend across the open top of the container and close in engagement with one another so that containers can be stacked on top of each other with the bottom wall of an upper container resting on the closed lids of the lower container. The containers can also be arranged in a nested stack when the lids are open and hang down along each side of the container. An example of a hinged lid container is shown in Bockenstette, U.S. Pat. No. 3,463,345, which is hereby incorporated by reference.
The half lids are hinged to the container along hinge lines at the top of each side wall of the container and are capable of rotating through approximately 270°. The hinge is formed from parts that are molded into the top of the container side wall and along the lid edges. In one example, the hinge parts form alternating recesses on the lids and container wall that capture a hinge pin that is manually inserted in the final assembly step. In another example, the hinge parts on the container are molded as pin segments and, on the lids, tubular shaped hinge knuckles are molded. The respective knuckle segments on the lids are assembled on the pin members on the container to form the hinge. In both cases, assembly of the hinge joint requires the lids to be manually assembled onto the container, for example by sliding the hinge pin in place and securing the ends of the pin or snap fitting or press fitting the knuckle segments of the lids onto the pin members of the container.
Part of the final cost of the hinged lid containers of the prior art reflects the costs associated with the manual labor required for assembly of the lids on the containers. This is a disadvantage since the molding of container and lids can otherwise be performed without manual assistance since a robot arm can be used to withdraw the molded parts from the mold core at the conclusion of the molding process.